Let's return to the c-maybe model and the Holevo quantities.
Touil et al. [1]} present results for
the quantum mutual information, \(\chi \left(\check{\mathcal {S}}:\mathcal {F}\right)\) ,
and \(\chi \left(\mathcal {S}:\check{\mathcal {F}}\right)\) . In the good decoherence limit,
the latter two are
\(\chi \left(\check{\mathcal {S}}:\mathcal {F}\right)=-\frac{1}{2}\log _{2}\left[p_{1}p_{2}\left(1-\left|\gamma \right|^{2{^{\sharp }}\hspace{-1.99168pt}\mathcal {F}}\right)\right]-\sqrt{1-4p_{1}p_{2}\left(1-\left|\gamma \right|^{2{^{\sharp }}\hspace{-1.99168pt}\mathcal {F}}\right)}\mathrm {Arctanh}_{2}\left[\sqrt{1-4p_{1}p_{2}\left(1-\left|\gamma \right|^{2{^{\sharp }}\hspace{-1.99168pt}\mathcal {F}}\right)}\right]\) 
